TITLE: Novel transparent polyurethane polyureas for lamination of glazing
materials
United States Patent 4174240
ABSTRACT:
The present disclosure is concerned with a novel transparent
polyurethane polyurea which is particularly suitable for lamination to
glass and glasslike transparent plastics. The polymer is the reaction
product of high molecular weight diols, optionally low molecular weight
diols, dihydroxy carboxylic acids, diisocyanates with only
aliphatically and cycloaliphatically bound isocyanates and organic
diamines having aliphatically and cycloaliphatically bound primary
amino groups. It has specified contents of carboxyl groups and urea
groups, and it has a minimum shear modulus at both 20° and 60° C.
The present disclosure is also concerned with a process for
synthesizing such polymers. A preferred method is to react the
diisocyanate and hydroxyl bearing compounds to prepare an isocyanate
terminated prepolymer and chain extend with the diamine.
Also discussed are the production of film from these polymers by
extrusion and solution casting, the production of laminates with glass
and glasslike plastics and the laminates so produced. The solution cast
or extruded films can be laminated to these substrates by the
application of heat and pressure.
INVENTORS:
Muller, Hanns P. (Leverkusen, DE)
Oberkirch, Wolfgang (Cologne, DE)
Wagner, Kuno (Leverkusen, DE)
Quiring, Bernd (Leverkusen, DE)
APPLICATION NUMBER: 05/947222
PUBLICATION DATE: 11/13/1979
FILING DATE: 09/29/1978
ASSIGNEE: Bayer Aktiengesellschaft (Leverkusen, DE)
PRIMARY CLASS: 156/99
OTHER CLASSES: 156/106, 156/309.6, 156/331.7, 428/332, 428/334, 428/339, 428/424.4,
428/425.6
INTERNATIONAL CLASSES: B32B17/10; C08G18/08; C08G18/12; C08G18/75; (IPC1-7): C03C27/04;
B32B27/40; C08G18/32; C09J5/04
FIELD OF SEARCH: 156/99, 156/106, 156/331, 428/339, 428/332, 428/412, 428/424, 428/425,
428/426, 428/522, 428/532, 260/75NH, 260/77.5AM, 528/64
US PATENT REFERENCES:
4048001 Polyurethane textile adhesive September, 1977 Remley 260/859R
4041208 Transparent, impact-resistant polyesterurethane laminates
August, 1977 Seeger 428/424
3931113 Impact-resistant thermoplastic polyester urethanes January,
1976 Seeger 260/75NT
3904460 Treating glass sheets September, 1975 Comperatore 428/425
3900686 Adhesion control for safety glass laminates August, 1975 Ammons
428/425
3900655 Laminated safety glass and/or plastic August, 1975 Wolgemuth
428/214
3900446 Polyurethane interlayer for laminated safety glass August, 1975
McClung 260/75NT
3881043 Laminated safety windshields April, 1975 Rieser 428/81
3878036 SAFETY GLASS PREPARED BY CURING A B-STAGE POLYURETHANE SHEET
April, 1975 Chang 428/424
3864204 MULTILAYERED SAFETY GLASS February, 1975 Shorr 428/425
3835081 N/A September, 1974 Remley 528/53
3823060 N/A July, 1974 McClung 260/75NT
3823051 N/A July, 1974 Chang 156/99
3808077 METHOD FOR LAMINATING PLASTIC TO GLASS EMPLOYING GLASS MOLD
April, 1974 Rieser 156/102
3791914 LAMINATED GLASS ARTICLES February, 1974 Ammons 428/425
3764457 N/A October, 1973 Chang 428/425
3721595 APPLYING ELECTROCONDUCTIVE HEATING CIRCUITS TO GLASS March,
1973 Tarnopol 156/89
3721594 APPLYING ELECTROCONDUCTIVE HEATING CIRCUITS TO GLASS March,
1973 Tarnopol 156/89
3711364 N/A January, 1973 Abramijian 428/425
3658939 N/A April, 1972 Carpenter 528/53
3640924 N/A February, 1972 Hermann 528/53
3580796 N/A May, 1971 Hick 428/425
3558422 N/A January, 1971 Hamilton 428/425
3522142 GLASS LAMINATED WITH SILICON-CONTAINING POLYURETHANE July, 1970
Wismer 428/425
3458388 GLASS-POLYURETHANE-POLYVINYLBUTYRAL-POLYURETHANE-GLASS LAMINATE
July, 1969 Moynihan 428/425
3445423 POLYURETHANE COMPOSITION FOR GLASS COATING AND LAMINATING
STABILIZED BY RESORCINOL MONOBENZOATE May, 1969 Sunshine 260/45.85
3412054 Water-dilutable polyurethanes November, 1968 Milligan 260/18
3401190 3-(isocyanatomethyl)-3, 5, 5-tri-lower-alkyl cyclohexyl
isocyanates September, 1968 Schmitt 260/493
3388032 Laminated safety glass June, 1968 Saunders 428/425
3352830 Polyurethanes from 1-isocyanato-3-isocyanatomethyl-3, 5,
5-tri-alkylcyclohexane November, 1967 Schmitt 260/77.5
3030249 Polyurethane coated articles April, 1962 Schollenberg 428/424
2864780 Transparent resinous substance December, 1958 Katz 260/18
FOREIGN REFERENCES:
CA967436 May, 1975
CA985152 March, 1976
GB1219630 January, 1971
GB1305624 February, 1973
GB1399124 June, 1975
GB1401986 August, 1975
PRIMARY EXAMINER: Robinson, Ellis P.
Attorney, Agent or Firm:
Harsh, Gene
Pope, Lawrence S.
Colen, Frederick H.
Parent Case Data:
This is a division of application Ser. No. 833,311 filed Sept. 14,
1977, U.S. Pat. No. 4,139,674.
CLAIMS:
What is claimed is:
1. A process for the production of laminates, wherein sheets of
silicate glass and/or transparent glass-like plastics are coated and/or
bonded together with a transparent film of 0.1 to 5 mm. in thickness
formed from a polyurethane polyurea with a predominantly linear
molecular structure exclusively containing aliphatically or
cycloaliphatically bound urethane and urea segments and having a shear
modulus G' (DIN 53 445) which amounts to between 2 and 140 N/mm^2 at
20° C. and does not fall below a value of 1 N/mm^2 at 60° C.,
characterized by
(a) a content of urea groups --NH--CO--NH-- amounting to between 1 and
20% by weight and
(b) a content of lateral carboxyl groups --COOH directly attached to
the main chain of the molecule amounting to between 0.001 and 10% by
weight.
2. A process for the production of laminates of glass or glass like
transparent plastics with polyurethane polyurea comprising subjecting a
transparent film of 0.1 to 5 mm in thickness formed from a polyurethane
polyurea comprising the reaction product of
(a) dihydroxy compounds having molecular weights between about 300 and
6,000 selected from the group consisting of polyesters and polyethers,
(b) dihydroxy carboxylic acids corresponding to the formula ##STR4##
wherein R represents H, or a C[1] to C[4] alkyl radical, (c) optionally
aliphatic or cycloaliphatic diols having molecular weights of between
about 62 and 300,
(d) diisocyanates having exclusively aliphatically and
cycloaliphatically bound isocyanate groups, and
(e) organic diamines containing aliphatically and cycloaliphatically
bound primary amino groups and having molecular weights between about
60 and 3,000, wherein the equivalent ratio of d:(a+b+c) is between
about 1.1:1 and 4:1, the equivalent ratio of e:(a+b+c) is between about
0.1:1 and 3:1, the molar ratio of a:b is between about 1:0.01 and 1:12,
and the molar ratio of a:c is between about 1:0 and 1:10, said
polyurethane polyurea having
(1) a molecular weight greater than about 10,000,
(2) a urea group content of between about 1 and 20 wt. %, and
(3) a content of lateral carboxyl groups directly attached to the main
chain of the molecule of between about 0.001 and 10 wt. %
and at least one immediately adjacent sheet of a glass or glass like
plastic to heat and pressure.
DESCRIPTION:
FIELD OF THE INVENTION
This invention relates to new polyurethane polyureas, to a process for
their production and to their use in the production of glass-clear
laminates, especially laminated safety glass.
BACKGROUND OF THE INVENTION
Laminated safety glass is widely used in motor vehicle windscreens, as
bullet-proof glass, for example for protecting bank and post office
counters, and as window glass, for example for reducing the danger of
injury in the event of breakage and also, for example, as a safeguard
against burglary and theft.
The interlayers used in these laminated glasses have to satisfy
numerous, very stringent requirements. The following properties, in
particular, are of considerable importance, especially for the use of
laminated glass in motor vehicles:
1. A high energy-absorbing capacity in the event of sudden stressing as
encountered on impact with blunt, but also sharp-edged bodies.
2. Adequate glass adhesion which is intended to prevent the glass from
shattering to any significant extent and causing injuries in the form
of cuts in the event of accidents.
3. High translucency; no hazing or clouding should occur.
4. A high degree of light stability, in other words the windscreens
should not turn yellow, even after prolonged exposure to sunlight.
5. High edge stability so that, when stored before fitting, the
windscreens should not undergo any delamination from the edges through
the absorption of water.
These properties in general and those mentioned under (1) and (2) in
particular should be retained over as wide as possible a temperature
range in which these materials are used.
In modified form, these requirements also apply to the use of the
interlayers in armoured glass and in safety glass of the type used in
building construction. Armoured glass is above all required to be
bullet proof to a large extent. This makes it necessary to use an
extremely tough interlayer.
Polyurethane interlayers for laminated safety glass are already known.
Thus, according to German Offenlegungsschrift No. 2,302,400
(corresponding to U.S. Pat. Nos. 3,823,060 and 3,900,446), polyurethane
interlayers for laminated safety glass are produced from
4,4'-methylene-bis-(cyclohexylisocyanate), a polyester containing
terminal hydroxyl groups and having a melting point above 42° C. and a
molecular weight of from 500 to 4,000, being the condensation product
of a dicarboxylic acid and a diol compound, and a chain extender which
is an aliphatic or alicyclic diol containing from 2 to 16 carbon atoms.
Unfortunately, conventional polyurethanes have the serious disadvantage
of poor adhesion to glass. However, glass-plastics laminates are
intended to be of a structure such that no splinters of glass can be
released from the plastics interlayer of the laminated glass in the
event of a collision. This requirement is not satisfied by conventional
polyurethanes (cf. Example 7).
Accordingly, the object of the present invention is to obviate the
above-mentioned serious disadvantage of conventional polyurethanes and,
in addition, to provide polyurethane polyaddition products of the type
which, in addition to excellent adhesion to glass, show outstanding
impact strength over a wide temperature range, are free from hazing and
local swellings, do not discolor on exposure to sunlight and show
excellent edge stability with respect to penetrating water.
This object is achieved by the polyurethane polyureas provided by the
invention.
SUMMARY OF THE INVENTION
Accordingly, the present invention relates to new polyurethane
polyureas having a predominantly linear molecular structure and
exclusively containing aliphatically or cycloaliphatically bound
urethane and urea segments with a shear modulus G' (DIN 53445) which
amounts to between 2 and 140 N/mm^2 at 20° C. and which does not fall
below 1 N/mm^2 at 60° C., characterized by
(a) a content of urea groups --NH--CO--NH-- amounting to between about
1 and 20% by weight and
(b) a content of lateral carboxyl groups --COOH directly attached to
the main chain of the molecule amounting to between about 0.001 and 10%
by weight.
The invention also relates to a process for producing these
polyurethane polyureas by reacting an excess quantity of an organic
diisocyanate containing aliphatically and/or cycloaliphatically bound
isocyanate groups with a dihydroxy polyester and/or dihydroxy polyether
having a molecular weight in the range from about 300 to 6,000, an
aliphatic dihydroxy monocarboxylic acid and, optionally, an aliphatic
or cycloaliphatic dihydric alcohol having a molecular weight in the
range from about 62 to 300, to form the corresponding isocyanate
prepolymer containing two terminal isocyanate groups, followed by
reaction of this isocyanate prepolymer with an organic diamine
containing aliphatically and/or cycloaliphatically bound primary amino
groups and having a molecular weight in the range from about 60 to
3,000, monofunctional synthesis components optionally being used in
small quantities for adjusting the particular molecular weight
required, wherein
(a) the dihydroxy carboxylic acid used corresponds to the formula
##STR1## in which R represents hydrogen or an alkyl radical with 1 to 4
carbon atoms, the quantity in which this dihydroxy carboxylic acid is
used being such that the polyurethane polyurea obtained contains from
0.001 to 10% by weight of lateral carboxyl groups, and
(b) the quantitative ratios between diisocyanates, dihydroxyl compounds
and diamines are selected so that the polyurethane polyurea contains
from 1 to 20% by weight of urea groups --NH--CO--NH--.
Finally, the invention also relates to a process for producing
laminates, wherein sheets of silicate glass and/or transparent plastics
are coated and/or bonded together with the new polyurethane polyureas.
DETAILED DESCRIPTION OF THE INVENTION
The new polyurethane polyureas are non-yellowing, translucent clear
thermoplasts with excellent edge stability and impact strength. Because
of the presence in them of from about 1 to 20% by weight, preferably
from about 2 to 10% by weight, of urea groups --NH--CO--NH--
incorporated in the chain, and of from about 0.001 to 10% by weight,
preferably from about 0.008 to 6% by weight, of lateral carboxyl groups
--COOH directly attached to the chain of the macromolecule, the new
polyurethane polyureas show excellent adhesion to glass and/or
transparent glass-like plastics, such as for example polymethyl
methacrylate, polycarbonate or cellulose esters, and are therefore
eminently suitable for the production of laminated safety glass, the
expression "laminated safety glass" as used in the context of the
invention applying both to sheets of silicate glass or glass-like
plastics coated on one or both sides with the polyurethane polyureas
according to the invention, and also to composite materials which
consist of at least two sheets of silicate glass and/or glass-like
plastics bonded together with the polyurethane polyureas according to
the invention and which may additionally be coated on one or both
surfaces with the polyurethane polyureas according to the invention.
Production of the polyurethane polyureas according to the invention by
the process according to the invention is preferably carried out on the
prepolymer principle, i.e. by reacting an excess quantity of a suitable
diisocyanate with dihydroxyl compounds to form the corresponding
prepolymers containing terminal isocyanate groups, and subsequently
chain-extending these prepolymers with diamine chain extenders.
Monofunctional reactants may optionally be used in small quantities in
order to regulate molecular weight and, hence, to adjust the physical
properties of the polymer. In general, the type of synthesis components
used and the quantitative ratios in which they are used are selected in
such a way as to give a theoretical molecular weight of from about
10,000 to ∞, preferably from about 20,000 to 200,000. The difunctional
synthesis components are generally used in such quantities in the
production of the polyurethane polyureas according to the invention
that from about 1.1 to 4 and preferably from about 1.2 to 3 isocyanate
groups and from about 0.1 to 3, preferably from about 0.2 to 2, amino
groups of the chain extender are used per hydroxyl group of the
alcoholic synthesis component.
Diisocyanates suitable for use in the production of the polyurethane
polyureas according to the invention are, in particular, diisocyanates
containing aliphatically and/or cycloaliphatically bound isocyanate
groups corresponding to the formula Q(NCO)[2], in which Q represents an
aliphatic hydrocarbon radical with 2 to 12 carbon atoms or a
cycloaliphatic or mixed aliphatic-cycloaliphatic hydrocarbon radical
with 4 to 15 carbon atoms. Examples of diisocyanates such as these are
ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene
diisocyanate, dodecamethylene diisocyanate,
cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate or
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane and
mixtures of these diisocyanates. Cycloaliphatic or mixed
aliphatic-cycloaliphatic diisocyanates are preferably used in the
process according to the invention.
1-Isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (isophorone
diisocyanate) is particularly preferred.
The alcoholic synthesis components are
(a) the relatively high molecular weight diols known per se from
polyurethane chemistry having molecular weights in the range from about
300 to 6,000, preferably from about 800 to 3,000,
(b) dihydroxy carboxylic acids corresponding to the formula ##STR2## in
which R represents hydrogen or an alkyl radical with 1 to 4 carbon
atoms and, optionally,
(c) low molecular weight aliphatic or cycloaliphatic diols preferably
having molecular weights in the range from about 62 to 300.
The quantitative ratios between the individual components (a), (b) and
(c) which may be simultaneously or successively reacted with the
isocyanate component, are preferably selected so that, for every
hydroxyl group of component (a), there are from 0.01 to 12 hydroxyl
groups of component (b) and from 0 to 10 hydroxyl groups of component
(c).
Component (a) may be any of the polyester, polyether, polythioether,
polyacetal or polyester amide diols known per se. The polyester or
polyether diols known per se in polyurethane chemistry are preferably
used.
The polyesters containing hydroxyl groups suitable for use in
accordance with the invention are, for example, the reaction products
of dihydric alcohols with dibasic carboxylic acids. Instead of using
the free dicarboxylic acids, it is also possible to use the
corresponding acid anhydrides or corresponding dicarboxylic acid esters
with lower alcohols or mixtures thereof for producing the polyesters.
The dicarboxylic acids may be aliphatic, cycloaliphatic and/or aromatic
and may be substituted, for example by halogen atoms, and/or
unsaturated. Examples of dicarboxylic acids such as these are succinic
acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic
acid, isophthalic acid, phthalic acid anhydride, tetrahydrophthalic
acid anhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic
acid anhydride, endomethylene tetrahydrophthalic acid anhydride,
glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric
acid, terephthalic acid dimethyl ester and terephthalic acid-bis-glycol
ester. Suitable dihydric alcohols are, for example, ethylene glycol,
1,2- and 1,3-propylene glycol, 1,4- and 2,3-butylene glycol, 1,6-hexane
diol, 1,8-octane diol, neopentyl glycol, cyclohexane dimethanol
(1,4-bis-hydroxymethyl cyclohexane), 2-methyl-1,3-propane diol,
3-methyl-1,5-pentane diol, also diethylene glycol, triethylene glycol,
tetraethylene glycol, polyethylene glycols, dipropylene glycol,
polypropylene glycols, dibutylene glycol and polybutylene glycols.
Polyesters of lactones, for example ε-caprolactone or hydroxy
carboxylic acid, for example ω-hydroxy caproic acid, may also be used.
Particularly suitable dihydroxy polyesters are also the dihydroxy
polycarbonates known per se which may be obtained, for example, by
reacting diols, such as 1,3-propane diol, 1,4-butane diol and/or
1,6-hexane diol, 3-methyl-1,5-pentane diol, diethylene glycol,
triethylene glycol, tetraethylene glycol, with diaryl carbonates, for
example diphenyl carbonate or phosgene.
Suitable dihydroxy polyethers are also those known per se and are
obtained, for example, by polymerizing epoxides, such as ethylene
oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide
or epichlorohydrin, on their own, for example in the presence of boron
trifluoride, or by adding these epoxides, either in admixture or
successively, with starter components containing reactive hydrogen
atoms, such as alcohols or amines, for example water, ethylene glycol,
1,3- or 1,2-propylene glycol, 4,4'-dihydroxy diphenyl propane, aniline.
In many cases, it is preferred to use polyethers predominantly
containing primary hydroxyl groups, in particular up to 90% by weight,
based on all the hydroxyl groups present in the polyether.
Component (b) is a dihydroxy carboxylic acid corresponding to the above
formula, such as for example dimethylol acetic acid, α,α-dimethylol
propionic acid or α,α-dimethylol-n-valeric acid. It is preferred to use
α,α-dimethylol propionic acid.
Component (c) is a glycol of the type already mentioned by way of
example in the description of the polyesters.
Suitable diamine chain extenders are aliphatic, cycloaliphatic or mixed
aliphatic-cycloaliphatic diamines preferably containing primary amino
groups and having molecular weights in the range from about 60 to 300.
Examples are ethylene diamine, tetramethylene diamine, hexamethylene
diamine, 4,4'-diaminodicyclohexyl methane, 1,4-diaminocyclohexane,
4,4'-diamino-3,3'-dimethyl dicyclohexyl methane or
1-amino-3,3,5-trimethyl-5-aminomethyl cyclohexane (isophorone diamine).
It is particularly preferred to use 4,4'-diaminodicyclohexyl methane or
the last of the above-mentioned diamines, isophorone diamine.
As already mentioned, the theoretical molecular weight of the
polyurethane polyureas according to the invention should amount to
between about 10,000 and ∞ and preferably to between about 20,000 and
200,000. This result may be achieved both by using a small excess of
difunctional isocyanate-reactive chain extenders or even by using small
quantities of monofunctional reactants. These monofunctional reactants
are generally used in quantities of up to about 3% by weight and
preferably in quantities of from 0.1 to 1% by weight, based on the
total quantity of the synthesis components. The following are mentioned
as examples of monofunctional reactants: monoisocyanates, such as
methyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate; mono
alcohols, such as methanol, ethanol, butanol, tert.-butanol, octanol,
isopropanol, cyclohexanol; monoamines, such as methylamine, butylamine,
dibutylamine.
In the case of the isocyanates and alcohols, the monofunctional
synthesis components may actually be used during the production of the
isocyanate-prepolymers while, in the case of the amines, they may be
used during the chain-extending reaction. A possible variant for
controlling molecular weight by using monofunctional synthesis
components is, for example, to react isocyanate-prepolymers produced
from difunctional synthesis components with a small deficit of diamine
chain extenders in the presence of monohydric alcohols, such as
isopropanol for example, the isocyanate groups initially reacting with
the more reactive diamine until it has completely disappeared, after
which the residual isocyanate groups are subjected to a
chain-terminating reaction with the isopropanol used as solvent.
In the production of the polyurethane-polyureas according to the
invention, the isocyanate-prepolymers are generally produced at a
reaction temperature of from about 80° to 150° C. The end point of the
reaction is determined by isocyanate group titration. Formation of the
prepolymers is followed by the chain-extending reaction with the
diamine chain extender either in the melt of even in solution.
Suitable solvents are, for example, methylene chloride, methanol or
isopropanol. The chain-extending reaction may also be carried out with
particular advantage in heated reaction screw extruders. In general, a
temperature of from about 120° C. to 300° C., preferably from about
150° C. to 250° C., is maintained during the chain-extending reaction.
Preferably the polyurethane-polyureas are prepared in a twinscrew
extruder according to the process disclosed in U.S. Pat. No. 3,963,679.
In addition, the type of synthesis components used and the quantitative
ratios in which they are used are selected within the ranges quoted
above in such a way that the urea content and the content of lateral
carboxyl groups in the polyurethane polyureas correspond to the values
quoted above, and in such a way that the shear modulus G', as
determined in the oscillating torsion test according to DIN 53445,
amounts to between about 2 and 140 N/mm^2 at 20° C. and does not fall
below a value of about 1 N/mm^2 at 60° C.
For example, the joint use of cycloaliphatic or branched aliphatic
synthesis components, for example neopentyl glycol, as component (c)
produces an increase in the shear modulus.
In general, the polyurethane-polyureas according to the invention
comply with the above-mentioned conditions regarding the shear modulus
G' simply because of their content of urea groups --NH--CO--NH--
essential to the invention, because any increase in the concentration
of urea is accompanied by an increase in the shear modulus.
In the production of the polyurethane polyureas according to the
invention, it is also possible in principle to incorporate other
lateral polar groups such as, for example --SO[3] H, --CN, --COOR,
--CONH[2], --CONRH or --CONR[2] (R=C[1] -C[4] -alkyl) in addition to
the lateral carboxyl groups essential to the invention in order to
improve the adhesion of the polyurethane polyureas to the glasses.
However, since the adhesion of the polyurethane polyureas according to
the invention to the glasses is in itself excellent without this
additional incorporation of polar lateral groups, this incorporation of
additional polar groups is not essential.
In the process according to the invention for producing laminated
safety glass, the polyurethane polyureas according to the invention are
used in the form of films ranging, for example, from about 0.1 to 5 mm
in thickness. These films may be produced by conventional film
extrusion techniques or by casting solutions of the polyurethane
polyureas according to the invention in suitable solvents, for example
of the type mentioned by way of example above, onto polished metal
surfaces in casting machines and evaporating the solvent. In this way,
the polyurethane polyurea films according to the invention can be
obtained in the necessary layer thicknesses by repeated casting.
Basically, it is also possible directly to produce the film on a sheet
of glass used for the production of the laminated safety glasses by
casting of a solution and physically drying the coating film obtained.
The films may also be obtained by extrusion techniques known per se.
In the production of the laminated safety glasses in accordance with
the invention, the polyurethane polyureas according to the invention
are used as coating agents and/or as binders for sheets of glass and/or
sheets of glass-like plastics.
Any type of silicate-containing glass of the type used for the
production of safety glasses may be used in the process according to
the invention for producing laminated safety glass. Glasses obtainable
by the float process are preferably used.
In addition to the silicate-containing glasses known per se, synthetic
"glasses" especially transparent polycarbonate films or sheets (cf. for
example U.S. Pat. No. 3,028,365 and U.S. Pat. No. 3,117,019) or
transparent films or sheets of polymerized methacrylic acid methyl
ester, may also be used in the process according to the invention for
the production of laminated safety glass. Sheets or films of cellulose
esters are also suitable. The thickness of the sheets of glass used in
the process according to the invention for producing the laminated
safety glass is not a critical parameter and is generally between about
0.1 and 10 mm. However, it is also possible to use glass films with a
thickness of only 100 μm or sheets of glass with a thickness of 20 mm.
The bond between the sheet of glass and the polyurethane polyurea
according to the invention in the production of coated glasses or the
bond between two or more sheets of glass using the polyurethane
polyureas according to the invention as binder, is established in
principle by melting the film of the polyurethane polyureas according
to the invention, which generally have a melting point between about
60° and 180° C., after it has been applied to the surface of the sheet
of glass to be coated or inserted between two sheets of glass. The
production of composite glass by bonding several sheets of glass
together with the polyurethane polyureas according to the invention is
generally carried out at temperatures of from about 100° to 200° C. and
under pressures of from about 5 to 20 bars.
The following advantages are afforded by the invention:
1. Glass-clear, highly transparent polyurethane polyurea films are
produced by a process which is simple and economic in practice having
the particular advantage over conventional films that they adhere
strongly, for example to glass, and are therefore particularly suitable
for the production of laminated safety glass.
2. Composite glass panels containing the interlayer films according to
the invention are particularly superior in regard to their behavior
under impact both at elevated temperatures and at low temperatures such
as are frequently encountered in panels exposed to weathering.
Thus, panels produced in accordance with Example 3 using films
according to Example 2.1 of a polyurethane polyurea according to
Example 1 remain intact in the dropped ball test according to DIN 52306
when the ball is dropped from a height of 5 meters at +35° C. and from
a height of 5.50 meters at a temperature of -20° C. This substantially
corresponds to the performance of a panel containing a standard
polyvinyl butyral interlayer at room temperature. In the
above-mentioned test, the maximum dropping height withstood by the last
of the above-mentioned panels at +35° C. is approximately 4 m. At -8°
C., the dropping height withstood by these panels is only 2.50 meters.
At -20° C., their impact strength would appear to be considerably
lower.
The superiority of the film according to the invention is also apparent
at room temperature. Dropping heights of 8 meters are still withstood
by comparison with the maximum dropping height of 6 meters withstood by
panels containing a PVB interlayer. However, the considerably better
behavior at elevated temperatures and low temperatures is particularly
valuable.
3. The polyurethane polyurea films according to the invention are free
from discoloration, hazing or local swelling (cf. Examples 1, 5, 6, 9,
10, 11, 12) and do not undergo any changes in exposure to sunlight.
4. In contrast for example to the polyvinyl butyral films currently in
use, the films according to the invention can be processed into
composite glass in nonconditioned atmospheres (cf. Example 3). In
conventional polyvinyl butyral films, the need to condition the films
arises out of the dependence of their properties upon water content
(cf. G. Rodloff, Neuere Untersuchungen an Verbund-Sicherheitsglas fur
Windschutzscheiben (Recent Investigations Into Composite Safety Glass
for Windscreens), Automobiltechnische Zeitschrift 64, No. 6, 1962).
5. The safety glasses produced from the films according to the
invention show excellent edge stability (cf. Example 3).
The invention is illustrated by the following Examples in which all the
percentages quoted are percent by weight.
EXAMPLES
EXAMPLE 1
Production of a polyurethane polyurea in the melt
(A) In a stirrer-equipped vessel, 70 kg (31.2 mol) of a linear
1,4-butane diol polyadipate containing terminal hydroxyl groups and
having an average molecular weight of approximately 2200 and 34.7 kg
(156.3 mols) of 1-isocyanato-3-isocyanatomethyl-3,3,5-trimethyl
cyclohexane (isophorone diisocyanate) are stirred overnight under
nitrogen at a temperature of 60° C. Thereafter 7.5 kg (83.3 mols) of
1,4-butane diol and 1.4 kg (10.45 mols) of dimethylol propionic acid
are added, followed by stirring for another 2 hours at 100° C.
Thereafter a content of free isocyanate groups of 2.2% is found.
(B) 600 g (0.313 mol) per second of the isocyanate-prepolymer obtained
in accordance with Example 1A and 26.6 g (0.313 mol) per second of
isophorone diamine are continuously introduced through separate pipes
into the feed hopper of a standard, heat twin-screw reaction extruder.
The screws are fitted with feed and kneading elements. The length to
diameter ratio of the screws amounts to about 40.
At a rotational speed of 200 min^-1, melt temperatures in the range
from 120° to 200° C. are measured over the length of the machine. The
product melt is quenched in a water bath, subsequently free from the
water adhering to it with compressed air and granulated. The reaction
product is obtained in the form of a colorless glass-cleaar resin.
______________________________________
--NH--CO--NH-content: 2.46% by weight --COOH-content: 0.4% by weight
shear modulus G' at 20° C.: 56 N/mm^2 at 60° C.: 1.7 N/mm^2
______________________________________
(as determined by the oscillating torsion test according to DIN 53445).
Production of composite glass panels with the polyurethane polyureas
according to the invention as interlayer.
EXAMPLE 2
Film production:
2.1 Extrusion:
The polyurethane polyureas produced in accordance with Example 1 in a
twin-screw reaction extruder are obtained in the form of a cylindrical
granulate and can be extruded, for example through a flat-sheeting die,
to form glass-clear films at a melt temperature of from 170° to 220° C.
2.2 Casting from solution:
The polyurethane polyureas according to the invention, in the form of
solutions with a solids content of approximately 20%, are cast by
suitable techniques (doctor, curtain), for example onto sheets of glass
or onto a moving steel belt, and the solvent is removed either at room
temperature or at elevated temperatures in a drying tunnel. In order to
obtain bubble-free films in the required layer thicknesses of from 0.7
to 0.8 mm, it is of advantage to produce the films by repeatedly
casting thin layers and evaporating off the solvent before the next
casting.
Producing the films by casting is particularly appropriate for
producing test specimens for determining the characteristics of the
material. Extrusion would appear to be preferable for manufacturing the
films on a commercial scale because it is the more economical method.
EXAMPLE 3
Production of the composite glass panels:
The polyurethane polyureas according to the invention, in the form of
films from 0.6 to 0.8 mm thick, are inserted between two sheets of
glass (silicate glass) measuring, for example, 30×30 cm, and introduced
into a suitable autoclave. The autoclave is initially evacuated in
order to remove the air between the glass and film. A preliminary bond
is established by heating in vacuo to 80°-100° C., followed by venting.
The temperature in the autoclave is then increased to 100°-190° C.,
preferably to 120°-170° C., depending upon the polyurethane-polyurea
used, and the final bond established by pressing for 5 to 30 minutes,
preferably for 10 to 20 minutes, under a nitrogen pressure of from 4 to
16 bars, preferably from 8 to 12 bars.
Composite glass panels produced in this way withstand the boiling test
according to DIN 52308. Bubble formation in the peripheral zone is
minimal.
EXAMPLE 4
Testing the bond strength of composite glass panels:
15×15 mm^2 samples are taken from the composite glass panels to be
tested. The samples, whose surfaces were roughened, were bonded between
two metal stamps with the same surface area (15×15 mm^2). A standard
epoxide resin adhesive was used as the adhesive
(Permabond-Contact-Cement No. 747, a product of Lubben and Co.,
Munich).
In a tensile tester, one of the stamps was suspended in the device
connected to the dynamometer, while the other stamp was suspended in
the separating device. The separation rate (V) amounted to 1 mm/minute.
A recorder recorded the adhesion forces occurring during the tests. The
adhesion forces were converted to a sample cross-section of 1 mm^2.
Bond strength determined by this method:
______________________________________
Example 5: 11.0 ##STR3## Example 6: 11.6 " for comparison Example 7:
2.5 " Example 8: 3.5 "
______________________________________
EXAMPLE 5
153 g (0.09 mol) of a polyester having a hydroxyl number of 65.9
synthesized from adipic acid, 1,6-hexane diol and neopentyl glycol, are
dehydrated for 30 minutes at 120° C. in a water jet vacuum. Thereafter
1.34 g (0.01 mol) of dimethylol propionic acid are added to the melt,
followed after thorough mixing by the addition of 66.6 g (0.3 mol) of
isophorone diisocyanate (hereinafter referred to as IPDI). The whole
was then stirred under nitrogen for 3 hours at 90° C. The isocyanate
content of the prepolymer is then determined:
isocyanate observed: 7.84%, isocyanate calculated: 7.61%.
600 g of methylene chloride are then added to the prepolymer. The
mixture is then left to cool to room temperature while stirring in a
nitrogen atmosphere, followed by the dropwise addition over a period of
30 minutes of a solution of 34 g (0.2 mol) of isophorone diamine
(hereinafter referred to as IPDA) in 320 parts of methylene chloride
and80 parts of methanol. A clear, colorless film solution with a
viscosity (η) of 26,800 mPas. is obtained. --NH--CO--NH-content of the
solid: 9.1%, --COOH-content: 0.176%, shear modulus G' 106.0 N/mm^2 at
20° C., 34.9 N/mm^2 at 60° C.
EXAMPLE 6
180 g (0.09 mol) of a polyester having a hydroxyl number of 56 produced
from adipic acid and ethylene glycol are mixed with 1.34 g (0.01 mol)
of dimethylol propionic acid and dehydrated for 30 minutes at 120° C.
in a water jet vacuum. Thereafter 66.6 g (0.3 mol) of IPDI are added
all at once. The mixture is stirred under nitrogen for 30 minutes at
120° C. The isocyanate content of the prepolymer is then determined:
isocyanate observed: 6.65%, isocyanate calculated: 6.78%.
600 g of toluene are then added to the prepolymer. The mixture is left
to cool to room temperature while stirring in a nitrogen atmosphere,
followed by the dropwise addition over a period of 30 minutes of a
solution of 34 g (0.2 mol) of IPDA in 370 g of toluene and 410 g of
isopropanol. Before the last 50 ml of this solution are added, a sample
(IR-spectrum) is taken from the mixture. If only very little isocyanate
can be detected by IR-spectroscopy, the chain-extending reaction is
terminated. The residual chain extending agent is discarded.
______________________________________
--NH--CO--NH-content of the solid: 8.23%, --COOH-content: 0.159%, shear
modulus G' 62.0 N/mm^2 at 20° C., 32.0 N/mm^2 at 60° C.
______________________________________
COMPARISON EXAMPLE 7
(without dimethylol propionic acid)
200 g (0.1 mol) of the polyester of Example 6 are dehydrated for 30
minutes at 120° C. in a water jet vacuum. 44.4 g (0.2 mol) of IPDI are
then added all at once. The mixture is stirred under nitrogen for 30
minutes at 120° C. Thereafter the isocyanate-content of the prepolymer
is determined. Isocyanate observed: 3.28%, isocyanate calculated:
3.44%.
600 g of toluene are then added to the prepolymer. The mixture is then
left to cool to room temperature while stirring in a nitrogen
atmosphere, followed by the dropwise addition over a period of 30
minutes of a solution of 17 g (0.1 mol) of IPDA in 370 g of toluene and
410 g of isopropanol. Before the last 50 ml of this solution are added,
a sample (IR-spectrum) is taken from the mixture. If only very little
isocyanate can be detected by IR-spectroscopy, the chain-extending
reaction is terminated. The residual chain-extending agent is
discarded.
______________________________________
--NH--CO--NH-content of the solid: 4.44% --COOH-content: 0% shear
modulus G' 5.5 N/mm^2 at 20° C. 2.0 N/mm^2 at 60° C.
______________________________________
COMPARISON EXAMPLE 8
(without dimethylol propionic acid)
170 g (0.1 mol) of the polyester of Example 5 are dehydrated for 30
minutes at 120° C. in a water jet vacuum. 44.4 g (0.2 mol) of IPDI are
then added all at once. The mixture is stirred under nitrogen for 30
minutes at 120° C. The isocyanate-content of the prepolymer is then
determined. Isocyanate observed: 3.98%, isocyanate calculated: 3.93%.
600 g of toluene are then added to the prepolymer. The mixture is left
to cool to room temperature while stirring in a nitrogen atmosphere,
followed by the dropwise addition over a period of 30 minutes of a
solution of 17 g (0.1 mol) of IPDA in 210 g of toluene and 340 g of
isopropanol. Before the last 50 ml of this solution are added, a sample
(IR-spectrum) is taken from the mixture. If only very little isocyanate
can be determined by IR-spectroscopy, the chain-extending reaction is
terminated. The residual chain-extending agent is discarded.
______________________________________
--NH--CO--NH-content of the solid: 5.01% --COOH-content: 0% shear
modulus G' 7.6 N/mm^2 at 20° C. 2.7 N/mm^2 at 60° C.
______________________________________
From the polyurethane polyurea solutions (according to Examples 7 and
8), films are produced by casting in accordance with 2.2 and composite
glass panels are produced in accordance with 3. Composite glass panels
produced in this way show poor adhesion to glass (cf. adhesion test,
Example 4).
EXAMPLE 9
336 g (0.15 mol) of a polyester (having a hydroxyl number of 50
produced from adipic acid and 1,4-butane diol are dehydrated for 30
minutes at 120° C./15 Torr. 36 g (0.4 mol) of 1,4-butane diol and 6.7 g
(0.05 mol) of dimethyl propionic acid are introduced into the melt,
followed after thorough mixing by the addition of 166.5 g (0.75 mol) of
IPDI. The melt is stirred under nitrogen for 40 minutes at 120° C. The
isocyanate content of the prepolymer is then determined.
Isocyanate observed: 2.1%, isocyanate calculated: 2.3%.
300 g of toluene are then added to the prepolymer. The mixture is then
left to cool to room temperature while stirring in a nitrogen
atmosphere, followed by the dropwise addition over a period of 30
minutes of a solution of 25.2 g (0.12 mol) of 4,4'-diaminodicyclohexyl
methane in 891 g of toluene and 510 g of isopropanol. Thereafter only
very little isocyanate can be detected by IR-spectroscopy.
______________________________________
--NH--CO--NH-content of the solid: 2.44% --COOH-content: 0.39% shear
modulus G' 38.0 N/mm^2 at 20° C. 1.6 N/mm^2 at 60° C.
______________________________________
EXAMPLE 10
336 g (0.15 mol) of a polyester (having a hydroxyl number of 50
produced from adipic acid and butane diol are dehydrated for 30 minutes
at 120° C./15 Torr. 40.5 g (0.45 mol) of 1,4-butane diol, 0.134 g
(0.001 mol) of dimethylol propionic acid and 166.4 g (0.75 mol) of IPDI
are then added to the melt. The mixture is stirred under nitrogen for
90 minutes at 120° C. The isocyanate-content of the prepolymer is then
determined. Isocyanate observed: 2.12%, isocyanate calculated: 2.32%.
300 g of toluene are then added to the prepolymer. The mixture is left
to cool to room temperature, followed by the dropwise addition over a
period of 30 minutes of a solution of 20.4 g (0.12 mol) of IPDA in 891
g of toluene and 510 g of isopropanol. On completion of the addition,
only very little isocyanate can be detected by IR-spectroscopy.
______________________________________
--NH--CO--NH-content of the solid: 2.47% --COOH-content: 0.008% shear
modulus G' 42.0 N/mm^2 at 20° C. 1.8 N/mm^2 at 60° C.
______________________________________
EXAMPLE 11
1900 g (0.95 mol) of a propylene glycol-started polyether, in which
propylene oxide has been polyadded in the presence of sodium alcoholate
up to a hydroxyl number of 56 (functionality 2), and 6.7 g (0.05 mol)
of dimethylol propionic acid are mixed and dehydrated for 30 minutes at
100° C./20 Torr. 0.5 g of dibutyl tin dilaurate (as catalyst) and 666 g
(3 mols) of IPDI are added to the mixture, followed by stirring under
nitrogen for 30 minutes at 100° C. Thereafter the isocyanate-content
amounts to 6.4% (isocyanate calculated: 6.53%). 6100 g of toluene are
added to the melt and the mixture is left to cool to room temperature.
A solution of 332.5 g (1.96 mol) of IPDA in 2620 g of isopropanol is
then added dropwise to the mixture over a period of 30 minutes. A clear
low-viscosity solution is obtained.
______________________________________
--NH--CO--NH-content of the solids: 7.82% --COOH-content: 0.077% shear
modulus G' 7.5 N/mm^2 at 20° C. 4.6 N/mm^2 at 60° C.
______________________________________
EXAMPLE 12
200 g (0.1 mol) of a polyester having a hydroxyl number of 56 of adipic
acid and ethylene glycol are mixed with 55.26 g (0.09 mol) of a
propylene glycol-started polyether having a hydroxyl number of 183, in
which first propylene oxide and then ethylene oxide have been polyadded
in the presence of sodium methylate, and with 1.34 g (0.01 mol) of
dimethylol propionic acid, followed by dehydration for 30 minutes at
120° C./15 Torr. 88.8 g (0.4 mol) of IPDI are then added to the mixture
all at once, after which the mixture is stirred under nitrogen for 2
hours. The isocyanate-content then amounts to 4.85% (isocyanate
calculated: 4.9). 700 g of toluene are then introduced into the melt
which is then left to cool to room temperature, followed by the
dropwise addition of 34 g (0.2 mol) of IPDA dissolved in 97 g of
toluene and 342 g of isopropanol. A clear highly viscous solution is
obtained.
______________________________________
--NH--CO--NH-content of the solid: 6.11% --COOH-content: 0.118% shear
modulus G' 55.0 N/mm^2 at 20° C. 9.8 N/mm^2 at 60° C.
______________________________________
EXAMPLE 13
Two 30×30 cm polycarbonate panels with a thickness of 4 mm and a 0.8 mm
thick film of the polyurethane polyurea of Example 1 (PUR) are
preheated for 30 minutes to 80°-90° C. The film is then placed between
the two polycarbonate panels and the system exposed for a few minutes
to a pressure of around 40 bars (for example in a multidaylight press)
in order to remove as much as possible of the air between the panels
and film. A pre-laminate is formed and may be handled without the
individual layers becoming separated from one another. The prelaminate
is then introduced into an autoclave which is heated to 140° C. The
autoclave is left at this temperature for 30 minutes under a nitrogen
pressure of 15 bars and then cooled under pressure. (This procedure
substantially corresponds to the conditions normally applied in the
production of conventional composite glass). It is best to keep the
laminate between supporting panels of glass or metal during its
production in order to prevent possible deformation of the
polycarbonate panels at the processing temperature. An extremely tough
glass-clear laminate is obtained. The adhesion between polycarbonate
and polymethane is extremely strong. It may be additionally varied by
suitably selecting the lamination temperature.
EXAMPLE 14
The procedure is as in Example 13, except that a multilayer laminate of
three 4 mm thick polycarbonate panels is built up by the process
described in that Example, a 2.5 mm thick layer of a polyurethane
polyurea according to the invention being inserted between two
polycarbonate panels. A transparent laminate is again obtained. This
laminate is bullet proof under fire with 6 mm ammunition.
EXAMPLE 15
Polycarbonate-PUR-glass composite
A 0.8 mm thick film of the polyurethane polyurea of Example 1 according
to the invention is placed on a 30×30 cm large 2.8 mm thick plate of
glass, followed by the application of a 3 mm thick polycarbonate plate.
The procedure is then as in Example 3, the prelaminate being produced
by heating in vacuo at 80° C. The prelaminate is then kept under a
pressure of 15 bars for 30 minutes at a temperature of 140° C. It is
then cooled under pressure. A glass clear laminate free from air
bubbles is obtained. Although the glass breaks under impact (for
example with a hammer or thrown stone), it does not become separated
from the polycarbonate. Laminates of polycarbonate and glass produced
with the polyurethane polyureas according to the invention are
extremely stable to light. They do not yellow, even after prolonged
exposure to sunlight.
EXAMPLE 16
The procedure is as in Example 15, except that a 200 μm thick glass
film is used instead of a glass plate. In another variant of this
Example, a structure of glass film/PUR film/polycarbonate panel/PUR
film is used, again with glass film as the outer layer. The laminates
formed are characterized by extreme toughness of the polycarbonate and
PUR layer and by the surface quality (hardness, scratch resistance) of
the glass.
EXAMPLE 17
Following the procedure of Example 13, a composite structure of two 4
mm thick panels of polymethyl methacrylate (PMMA) (for example
Plexiglas ® ) with a 0.8 mm thick polyurethane interlayer is produced
in an autoclave at 130° C./15 bars. The glass clear laminate is tougher
than a compact PMMA panel of comparable thickness.
EXAMPLE 18
5 layers of a 0.8 mm thick film of the polyurethane polyurea of Example
1 are placed on a 50×20 cm large, 10 mm thick plate of glass, followed
by the application of a 3 mm thick plate of glass. This assemblage is
heated to 80°-90° C. and then passed through squeezing rollers for
venting. The final laminate is then produced in the usual way, i.e. in
an autoclave over a period of 30 to 45 minutes at 140°-145° C./15 bars.
The transparent laminate thus produced withstands fire from a 0.4 mm
magnum revolver at a range of 4 meters.
EXAMPLE 19
The procedure is as in Example 3, except that a plate of glass coated
beforehand with release agent, for example a standard commercial-grade
polysiloxane or fluorine polymer, is used for covering the PUR film on
one side. After the laminate has been produced, this plate of glass can
be lifted off. A two-layer laminate of glass and the film according to
the invention is obtained. The advantage of laminates such as these is
that, when the laminate is subjected to impact on the film side,
virtually no injuries can be caused through cuts. The energy-absorbing
capacity is not impaired by comparison with the laminates of Example 3.
Although the invention has been described in detail for the purpose of
illustration, it is to be understood that such detail is solely for
that purpose and that variations can be made therein by those skilled
in the art without departing from the spirit and scope of the invention
except as it may be limited by the claims.